Endovascular thrombectomy for large ischemic strokes: Meta-analysis of six multicenter randomized controlled trials

Background: Six randomized controlled trials have concluded their investigations on the efficacy and safety of endovascular thrombectomy (EVT) for patients with large infarcts. To synthesize the results from six trials which met the inclusion criteria (RESCUE-Japan LIMIT, ANGEL-ASPECT, SELECT2, TESLA, TENSION, and LASTE) to provide high-level evidence and guide providers on optimizing EVT treatment decisions for patients presenting with large ischemic strokes seen on initial imaging. Methods: Study and patient characteristics of the six included trials were collected, and 90-day modified Rankin Scale (mRS) outcomes were tabulated. Generalized odds ratios (OR) of mRS score shift and utility-weighted mRS values were calculated for each study. Random-effects models were used to pool study outcomes. Results: 922 patients received EVT, and 924 received medical management. Most patients had Alberta Stroke Program Early CT (ASPECT) scores of 3 to 5 and intracranial occlusion in the internal carotid artery (ICA) or the first segment of the middle cerebral artery (M1). EVT was significantly superior to medical management in terms of likelihood of better mRS score, functional independence (mRS score 0-2), and independent walking (mRS score 0-3) at 90 days, representing numbers needed to treat of 4.7 (95% CI 3.7 to 6.6), 7.1 (95% CI 5.6 to 9.6), and 10.6 (95% CI 8.2 to 14.8), respectively. EVT was not significantly associated with higher risk of symptomatic intracranial hemorrhage (1.7% (95% CI -0.32% to 3.72%), P=0.10). There was significant inter-study heterogeneity in mortality risk, which might have been due to differences in treatment time windows. Conclusions: This study provides strong evidence that EVT is effective for patients presenting within 6 hours of stroke onset, ASPECT scores of 3 to 5, and intracranial ICA or proximal M1 occlusion. Use of EVT beyond 6 hours or for more distal occlusions requires further investigation.